Intra-annual variation of root-associated fungi of Pinus sylvestris var. mongolica: The role of climate and implications for host phenology

Abstract

Listen

Translate article

Root-associated fungi (RAF) influence plant growth and maintain multiple ecosystem functions. However, the relationship between the temporal dynamics of RAF communities and climate conditions and host phenology are less clear, especially in desert ecosystems. Therefore, intra-annual patterns of RAF can reveal their influence on Pinus sylvestris var. mongolica, an important sand control species. We sampled the roots of P. sylvestris of three age groups (27, 33, and 44 years) from April to September in the Mu Us Desert. Subsequently, taxonomic and functional groups of the RAF were identified using Illumina amplicon sequencing and the FUNGuild platform, respectively. The results indicated that (1) the alpha diversity indices were significantly different among sampling months but not among stand ages; the richness of symbiotrophic fungi was higher than that of saprotrophic fungi or pathotrophic fungi. (2) The major functional guilds were identified as ectomycorrhizal (especially Rhizopogon, Geopora, Russula, and Amphinema) and undefined saprotrophs. The monthly differences in RAF were mainly affected by climate factors, especially mean temperature and precipitation. (3) There were highly connected and low modularized networks in July and August, and the topological alterations across stand age did not fluctuate. The keystone genera that potentially to provide ecological functions showed dynamic changes in the P. sylvestris plantation. The determinants of temporal variations in RAF communities on an intra-annual scale in desert environments were climate conditions and host phenology, which showed that during the main growing season of the host when the relatively high temperatures and humidity were high, there were higher levels of fungal diversity, more diverse community composition and a more complex fungal co-occurrence network. These results highlight the importance of interactions between community functions of RAF and forest growth and health.